std::vector<bool,Allocator>::swap - cppreference.com (original) (raw)

| | | | | --------------------------------------------- | | ----------------------- | | static void swap( reference x, reference y ); | | (constexpr since C++20) |

Swaps the contents of x and y as if by bool b = x; x = y; y = b;.

[edit] Parameters

[edit] Return value

(none)

[edit] Complexity

Constant.

[edit] Example

#include #include void println(std::string_view fmt, std::vector const& vb = {}) { for (std::cout << fmt; bool const e : vb) std::cout << e << ' '; std::cout << '\n'; } int main() { println("swap elements of the same vector:"); std::vector x{1, 0}; println("before swap, x: ", x); x.swap(x[0], x[1]); // same as std::vector::swap(x[0], x[1]); println("after swap, x: ", x); println("swap elements of two different vectors:"); std::vector y{0, 0, 1}; println("before swap, x: ", x); println("before swap, y: ", y); y.swap(x[0], y[2]); // same as std::vector::swap(x[0], y[2]); println("after swap, x: ", x); println("after swap, y: ", y); }

Output:

swap elements of the same vector: before swap, x: 1 0 after swap, x: 0 1 swap elements of two different vectors: before swap, x: 0 1 before swap, y: 0 0 1 after swap, x: 1 1 after swap, y: 0 0 0

[edit] Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.